Contouring is the process of identifying an object within an image by outlining or otherwise distinguishing the object from the rest of the image. Medical images, such as CT (computed tomography), MR (magnetic resonance), US (ultrasound), or PET (positron emission tomography) scans, are regularly contoured to identify certain pieces of anatomy within the image. For example, a radiologist or oncologist may contour a medical image to identify a tumor within the image. Software tools are available to assist in this type of “manual” contouring, in which the physician uses the software to create the contour by tracing the boundary of the object or objects within the image.
Three-dimensional scans, such as CT and PET scans, produce a series of two-dimensional (2D) image slices that together make up the 3D image. Contouring these types of 3D images typically requires individually contouring each of the 2D images slices, which can be a laborious process. Systems and methods for contouring 3D images are disclosed in U.S. patent application Ser. No. 12/772,377, filed on May 3, 2010 and titled “Systems and Methods for Contouring a Set of Medical Images,” and U.S. patent application Ser. No. 12/772,383, filed on May 3, 2010 and titled “Systems and Methods for Generating a Contour for Medical Image,” which are incorporated herein by reference.
Contoured image slices are used in radiation therapy procedures to aid a medical practitioner in the planning of radiation delivery, such as the placement of radiation containing seeds. The, contoured areas provide a target for the placement of seeds, however, the medical practitioner may wish to conduct such a procedure at an angle different than the original contoured image slices.
Re-slicing is generally directed to applying an arbitrary angle to rotate and reformat medical images. The angle may include a user-defined angle for reformatting images to be orthogonal to a planned brachytherapy seed planning path or in plane with an external beam entry path. Re-slicing a contoured image involves manipulating both the original image slices and the contoured image slices. There exists a need to reformat image slices in an efficient manner that allows contoured image data to translate to the reformatted image slices and treatment planning to be performed on the reformatted image slices.